Oil burner and method of effecting the combustion of oil fuels



June 3, 1930 w. F. RAVENOR 6 OIL BURNER AND METHOD OF EFFECTING THECOMBUSTION OF OIL FUELS Filed Dec. 3, 1924 In Ven 60 2. r61 fe a/sfififmvr Z a Pate nted' June a, Yieao UNITED STATES PATENT OFFICE OILBURNER AND METHOD EFFECTIIQ' G THE COMBUSTION OF OIL FUELS Applicationfiled December 8, 1924. Serial No. 753,670.

My invention relates to improvements in oil burners and the method ofefi'ecting the combustion of oil fuels, and the ob'ect of my inventionis to devise a burner for eavy fuel oil in which the oil is fractionallyvaporized in an enclosed retort which characterizes the burner at hightemperature without the accumulation of free carbon and ash'so thatchoking of the burner due to carbon and ash deposits is entirelyprevented, enabling it to operate continuously with great cleanliness,economy and efliciency. In oil fuels there is a tendency when subjectedto heat for the more volatile fractions to form vapors and 1 for theless'volatile fractions to retain their liquid state, and I refer tothese two fractions of the oil-fuel, respectively, as vaporized andnon-vaporized portions of the oil fuel.

A further object is to provide a burner ofthis character in which theentering oil is subject to a moderate temperature and in which all thesurfaces subjected to high temperature are kept moist so that thefreegases do not contact with any dry hot surface. A

still further object is to provide an oil burner in which the lighterfractions only of the oil are vaporized, provided with means whereby theheavy residual fractions flow from the burner outlet into the furnace inthe form of a drip to carry the free carbon and ash out of the burnerwhich normally tend to choke it, an additional characteristic of theburner being that the flame is formed specifically into an oxidizingflame directed to a point on which the heavy residual drip falls so thatcomplete combustion throughout is efiected in a highly practicalmanner.A still further ob ect is to devise a retort burner which functions tovaporize the volatile fractions from the oil designed and arranged sothat the remaining residual oils are then cooled below their point ofvaporization by directing them past surfaces cooled b the incoming oiland are further coole by passing them around the surface of a pipemaintained at a low temperature by an air current induced by the draftof the furnace so that the residual oil at its outlet point is below itskindling temperature.

The method of effecting the combustion of oil fuels at present in oilburners is to provide a motor driven fan or a jet to force air to thefuel to supplly for its'combustion. t is well recognized that merelyallowing oil fuel to drip, without be: ing under pressure,from a nozzlewill not provide for its combustion, but will result-in the accumulationof free carbon and soot about the nozzle that will very quickly clog thedevice. A primary object of my 1nven-- introducing the non-va orizedportion to the oxidizing point of the ame,be it noted, not the-reducingportion of the flame. I utilize the non-vaporized portion to carry offany soot or ash that might result at the time of the separation of thevaporized from the non? vaporized portion of the oil fuel. attain theseobjects by the construction illustrated in the accompanying drawings inwhich'- Fig.1 is a view of the burner, in sectional elevation.

Figs. 2 and 3 are front and side views respectively of the burner asembodied in a furnace, the furnace being. indicated in dotted outline.

the necessary oxygen Similar figures of reference indicate similar partsthroughout the several views.

1 indicates an open-ended cyiindrical shell perforated as shown toprovide a plurality of air inlet apertures 2, in the upper end of whichis fitted a shorter open-ended cylindrical shell or cover 3 the lowerend of which projects a short distance into the shell 1 as at 4 and hasits outer periphery Within the shell reduced in diameter so that a space5 is provided between the shells while disposed in close proximity tothe lower end of the shell 1 to provide an air inlet 39 thereinto is aring 6 having a bore 7 of less diameter than the bore 8 of the shell 1,as shown more particularly in Fig. 1.

Positioned within the shell 1 at a suitable height above its lower endand concentrically therein is a small cylindrical chamber 9 closed atits lower end as at 10, its upper end being open, which chamber istermed, for the purpose of this specification, the retort, and expandedat its upper end to form an oil expansion chamber B, and extends to apoint above the upper end of the shell 3, as indicated by the numeral11, and is provided intermediate its height with an integral exteriorannular lip 12, positioned a short distance below the upper end of theshell 3 so as to lie within the shell, and surmounting and substantiallyenclosing the upper end of the chamber 11, which is open, and suitablyspaced therefrom is a hood 13 the lower edge of which is flangedoutwardly, as at 14, this flange 14 being spaced close to the lip 12hereinbefore mentioned, so that an annular orifice, outlet or nozzle 15is provided from the interior of the chamber formed by the hood 13 andthe enlarged upper end 11 of the retort 9. Between hood 13 and cover 3is disposed suitable air port 52 preferably annular in form whichfunctions to maintain a high air velocity induced by the draft of thefurnace.

Secured concentrically to the bottom of the retort 9 and of lessdiameter than the same is a vertical tube 16 the upper end of whichisopen and extends substantially to 1 the same level as that of theorifice 15 while within the tube 16 is a sealing pipe 16 of smallerdiameter the upper end of which is secured to the underside of the hood13 and the lower end of which extends to within a short distance of thebottom of the retort 9 and within the pipe 16 is a smaller open endedair pipe 17 the upper and lower ends of which extend respectivel throughthe hood l3'and the bottom 10 o the retort, the projecting lower end ofthe pipe 17 being surrounded by a ring 18 secured concentrically to thebottom of the retort, which ring forms the inner wall of an air coolingchamber 19 formed by the ring 18 and a cylindrical casing 20 disposedaround the retort 9 and the ring and spaced 2. suitable distancetherefrom, the lower end edge of the casing 20 being flan ed inwardly asat 21 to extend to within a s ort distance from the ring 18 so that anannular opening 22 is provided in the bottom of the chamber 19.

The pipe 17 is provided with a downwardly directed internal pipe 23 themouth of which extends through the pipe wall and is-spaced a shortdistance below the level of ghe upper end of the tube 16, as indicatedin 2 5 indicates a fuel pipe passed through the burner shell 1 andconnected at one end to the retort 9 close to the bottom of the same itsopposite end being formed as a receptacle 25 to receive a regulated oilsupply from a fuel pipe 26 and maintain a constant oil level in theretort 9, since the oil level in the receptacle 25 is controlled at thesame level, while 27 indicates an air duct passed through the shell 1and connected at its inner end to the air cooling chamber 19 whichsurrounds the retort 9, as hereinbefore stated. The annular spacebetween the walls 1 and 3 and the axially disposed walls 11 and 20constitutes a flame chamber 51.

28 indicates a box inserted into the front of the furnace the furnacebeing indicated by the dotted lines and numeral 40 in Figs. 2 and 3,usually in the furnace door opening, which box has the top 29, bottom30, sides 31 and 32 and back 33, the front of the box being open and thebottom 30 provided with an opening 34, as indicated in Fig. 3, theposition of the box when in place being such that the opening 34 liesover a an 35 placed on firebrick 36 covering the fire ars 37. The box 28is enclosed in a larger open-fronted box 41 havin an opening 42 withwhich the opening 34 of box 28 registers and. the space between theboxes is filled with a layer of asbestos 43.

The manner in which the burner is used and operates may be brieflydescribed, it being understood that there are mainly, three chamberswithin the burner, namely, the retort chamber 9, which receives theunvaporized fuel oil from the pipe 25 and now identified by the letterA, the boiling oil chamber identified by the letter B and which extendsfrom the oil level as maintained constant in the retort to the level ofthe upper end of the tube 16, and the gas chamber identified by theletter C, which is the space above the boiling oil level B1 enclosed bythe hood 13, and that these chambers A, B and 'C, are surrounded by theshells 1 and 3 and are in communication with the interior of theseterior thereof with which communication is established only through theopening 34 and thus the burner functions in the outside atmosphere. Oilbeing fed into the retort 9, that is, the chamber A, which is keptcomparatively cool by the surrounding air chamer l9, boils when theburner is operating, into the chamber B, the boiling oil rising to thelevel B1, and, the lighter fractions being vaporized, gas formsandcollects in the gas chamber C, from which it passes through theoutlet orifice 15 and mixes with the down draft of air passing theorifice 52 which en'- ters the upper end of the bore of the shell 3, thecombustible gas and air mixture then passing down through the bores 8and? of the shell 1 and ring 6, and through the opening 34 in the bottomof box 28 and registering opening 42 of box 41 into the furnace where itburns continuously as long as the burner remains in operation, thelength of the flame, which is indicated by the numeral 45, being limitedby the pan 35 which is placed under the flame at the oxidizing pointofthe same.

- It will be noted that additional air enters during operation throughthe apertures 2 and the inlet 39 between the shell 1 and the ring 6.

The heavy residual particles, being unvaporized in the chamber B,overflow the top of the tube 16 as a weir, and pass down between thetube 16 and the-sealing pipe 16 to the bottom of the tube 16 and thenpass upwardly around the outside of theair ipe 17 to enter the outlet 23and flow there rom in the form of a drip the temperature of which isbelow its kindling temperature due to the cooling of the residual flowby its passage around the sealing and air pipes respectively 16 and 17from its overflow point to its outlet point, which drip, indicated bythe numera1 44, carries with it the accumulation of free carbon and ashand drips on the pan 35, and as the point of contact of the drip withthe pan is also the point of contact therewith of the oxidizing flame,combustion of the heavy residual fractions is instantaneously efl'ectedfrom which it will be seen that choking of the burner by carbon and ashdeposits is en tirely prevented, enabling it to function with greatefficiency, cleanliness and economy.

I claim: v

1. The method of effecting the combustion of oil fuels, comprisingheating the fuel to form vaporized and unvaporized portions thereof,separating said portions, burning the vaporized portion in a primaryflame, while withholding the non-vaporized portion of the oil fuel fromthe said flame, and thereafter feeding the non-vaporized portion of theoil to said flame.

2. The method of effecting the combustion of oil fuels, comprisingheating the fuel to form vaporized and unvaporized fractions thereof,burning the vaporized fraction;

temporarily withholding the non-vaporized fraction from the flame;maintaining the temperature. of said unvaporized fraction below itsflash point; and then introducing the said unvaporized fraction to theflame.

3. In the method of eflectin the combustion of oil fuels, the ste s ofcontinuously drawing ofi separately t e oil fuel in two portions, thevaporized and non-vaporized; and maintaining the temperature of saidnon-vaporized portion below its flash point and feeding it to thecombustion flame in liquid form.

4. An oil burner embodying a shell; an oil retort within said shell; anoil expanding chamber communicatin with said oil retort; an annularflame cham er surrounding said oil retort and said oil expansionchamber; and a withdrawal chamber axially disposed within said oilretort and oil expansion chamber, and communicating with the former toreceive unvaporized oil therefrom and having an outlet to the flamechamber to supply said unvaporized oil thereto.

, 5. An oil burner embodying a shell with air ports therethrough; anannular cover on said shell; an air jacketed oil retort in said shelland spaced from the wall thereof to form a flame chamber, an oilexpanding chamber communicating with said retort from which the oil fuelis withdrawn in two separate portions, the vaporized and nonvaporized,and having an outlet for the former to said flame chamber, the coverhaving an air port of smaller area than the area of the flame chamber.

6. An oil burner embodying a shell; an oil retort operatively disposedtherein; an oil expanding chamber communicating with said retort fromwhich-the oil fuel is withdrawn in two separate portions, the vaporized,and non-vaporized; nozzle means discharging from said chamber into theinterior of the shell, and separate .means for delivering saidnon-vaporized portion of the fuel into the shell. 7

7. An oil burner embodying a shell forming a combustion chamber; an oilretort operatively disposed therein; an oil expanding chambercommunicatin with said retort from which the oil fuel 1s withdrawn intwo separate portions, the vaporized and nonvaporized; nozzle means fordelivering said vaporized portions from said expanding chamber into onepart of the shell; aseparate withdrawal means from the retort for saidnon-vaporized portion of the fuel; and

means for delivering said vaporized portion from said expanding chamberinto the combustion chamber, a Withdrawal means from the retort for saidnon-vaporized portion of the fuel; an open ended air tube connected tosaid withdrawal .means and leading to said chamber, for delivering saidnon-vaporized portion of said oilfuel to the combustion chamber.

9. An oil burner embodying a shell forming a combustion chamber, anannular oil retort axially dis osed in said shell; an oil expanding chamer superimposed upon and communicating with said retort, from which theoil fuel is withdrawn in two separate portions, the vaporized andnon-vaporized; an annular nozzle means for said vaporized portionsdischarging from the expanding chamber into the combustion chamber; anannular withdrawal chamber concentrically disposed within said retortinto which the non-vaporized oil fuel may pass; an open ended tubeconcentrically disposed within said withdrawal chamber through whichtube air may )ass to the combustion chamber, and a coniluit leading fromsaid withdrawal chamber into said tube whereby said non-vaporizedportion of said oil fuel may be introduced into said tube.

10. An oil burner embodying a shell; an

- oil retort within said shell; an oil expanding chamber communicatingwith said oil retort from which the oil fuel is withdrawn in twoseparate portions, the vaporized and non-vaporized; said shell formingan annular flame chamber surrounding said oil retort and expansionchamber; an air-jacket around said oil retort; and a withdrawal chamberaxially disposed within said oil retort and oil expansion chamber, andprovided with means whereby said non-vaporized oil may be conductedinwardly to said withdrawal chamber, and means to mix said non-vaporizedoil with air and discharge same into the flame chamber.

11. An oil burner comprising a constant level fuel oil retort having itsupper end extended to form an expansion chamber, and provided with anexterior lip intermediate its height, a hood surmounting the upper endof said chamber enclosing therewith a gas chamber receiving thevaporized light fractions from the boiling oil, said gas chamber havingan outwardly extending flange at its lower end edge disposed adjacentthe said exterior lip forming therewith an annular outlet from the gaschamber, an air pipe extending at its 0 posite ends respectively throughthe hoo and the bottom of the retort, said air pipe being provided witha downwardly directed internal pipe the mouth of which extends throughthe pipe wall below the normal constant oil level, a sealing pipedisposed around and spaced from the said air pipe" secured at its upperend to the under side of said hood and extending at its lower end towithin a short distance of the retort bottom, and an openendedcylindrical shell surrounding the said retort and chambers.

12. An oil burner comprising a constant level fuel oil retort having itsupper end extended to form an expansion chamber, and provided with anexterior lip intermediate its height, a hood surmounting the upper endof said boiling oil chamber enclosing therewith a gas chamber receivinthe vaporized light fractions from the boiling oil, said gas chamberhaving an outwardly extending flange at its lower end edge disposedadjacent the said exterior lip forming therewith an annular outlet fromthe gas chamber, an air pipe extending at its opposite ends respectivelythrough the hood and the bottom of the retort, said air pipe beingprovided with a downwardly directed internal pipe the mouth of whichextends through the pipe wall below the normal constant oil level, ascaling pipe disposed around and spaced} from the said air pipe securedat its upper end to the underside of said hood and extending at itslower end to the retort bottom and extending at its upper end to thenormal oil level and an open-ended cylindrical shell surrounding thesaid retort and chambers.

13. The combination with a furnace, of a box inserted into the furnacefront closed on all sides except the front which is open and having anaperture in the bottom forming theonly communication between theinterior of the box and the firebox, an openended cylindrical shellseated in said box With its bore communicating with the box aperture, afuel oil retort mounted within the shell having its upper end extendedto form an expansion chamber, a hood surmounting the upper end of saidchamber enclosing therewith a gas chamber, said gas chamber having aside outlet, a vertical air duct extending at its opposite endsrespectively through the hood and the retort bottom, said air duct beingprovided with a downwardly directed internal discharge, the mouth ofwhich is directed toward said aperture, a pipe disposed around andspaced from said air duct secured at its upper end to the underside ofthe hood and extending at its lower end below the said air ductdischarge mouth to prevent escape of gas therethrough from the gaschamber, and a tube disposed around and spaced from said pipe secured atits lower end to the retort bottom extending at its upper end to providea weir over which non-vaporized oil overflows.

14. The combination with a furnace, of a box inserted into the furnacefront closed on all sides except the front which is open and having anaperture in the bottom forming the only communication between theinterior of the box and the firebox, an openended cylindrical shellseated in said box with its open end communicating with the box apertureand a fuel oil retort mounted within the shell and having as andnonvaporized oil outlets into the s ell, the shell formin a flamechamber which discharges throng its open end and said aperture into thefurnace. Dated at Vancouver, B. 0., this 24th day of November, 1924.

WILFRED FRANCIS RAVENOB;

